Many modern consumers prefer flexible plastic containers over traditional inflexible containers such as glass bottles or metal containers for a variety of reasons.
Glass bottles can crack, chip, break or explode--often at most inconvenient times. Metal containers can, at times, be difficult to open. Many metal containers, moreover, once open, can have sharp edges or burrs.
Certain viscous fluids, such as ketchup and certain salad dressings, furthermore, can often more readily be poured from flexible or plastic containers than from glass bottles or metal containers of comparable general shape. Also, many consumers are generally able to extract a greater percentage of fluid residue from a flexible or squeezable plastic container than would be possible were the fluid contained in certain inflexible containers of comparable volume. In certain storage situations, moreover, flexible containers can be squeezed into relatively tight nooks or crannies which would not otherwise accommodate an inflexible fluid container of comparable general shape. Finally, because flexible plastic containers, when empty, are generally more readily compactible than certain metal and most glass containers, relative ease of fluid container disposal can, at times, be an important consumer consideration in deciding which brand of a particular fluid product to purchase.
Thus, in light of a general preference by consumers for flexible plastic fluid containers, a variety of flexible plastic containers, designed to meet a number of specific consumer demands and to provide certain desirable features, have of late come into being.
U.S. Pat. No. Re. 24,251 to Kaplan et al., for example, discloses a fluid-dispensing container, made from two sheets of flexible plastic material, for containing desired amounts of liquid. Such a container is said to be particularly adapted for shipment in sealed condition, and is further said to be provided with a tearable strip along one end thereof to facilitate opening of the container. Such a strip, when so torn, can thus be utilized for purposes of dispensing the contained liquid from its container, as desired, upon application of a predetermined fluid-dispensing pressure to the sidewalls of the container. See also U.S. Pat. No. 4,717,046 to Brogli.
However, not all flexible plastic fluid containers need to made from two sheets of plastic, sealed together at their edge margins, as Kaplan et al. disclose. In U.S. Pat. No. 2,517,027 to Rado, for example, there is disclosed a collapsible tube-like container for certain viscous fluids such as pastes.
Another version of a tear-away, sealing strip is disclosed in U.S. Pat. No. 3,278,085 to Brown, which patent discloses a sachet container which is said to be "re-sealable". The sachet, also referred to as a so-called "pouch pack", is deformable and is generally utilized to contain, dispense and retain certain liquids, semi-liquids, pastes, and the like.
In U.S. Pat. No. 3,473,532 to Eisenberg, moreover, a bag-type of flexible plastic fluid container having a self-closing one-way valve is disclosed. Certain features which provide automatic retention of fluid contained by a flexible plastic container, after such container has been opened, are important design considerations in each of U.S. Pat. Nos. 3,815,794 and 3,878,977, both to Carlisle, U.S. Pat. No. 3,904,107 to Nishimura et al., each of U.S. Pat. Nos. 4,163,509 and 4,312,689, both to Amneus, and U.S. Pat. No. 4,252,257 to Herzig.
Originally-sealed fluid-discharge passageways which are openable upon application of moderate pressure to the sidewalls of the flexible-plastic fluid container are important design considerations in U.S. Pat. No. 3,913,789 to Miller and U.S. Pat. No. 4,537,308 to Hollander, Jr.; and originally-sealed fluid passageways, openable other than by application of such pressure to the sidewalls of the fluid container, are important design considerations of the flexible plastic fluid containers disclosed in U.S. Pat. No. 3,917,116 to Mason and U.S. Pat. No. 4,491,245 to Jamison.
Simplicity of overall design can also be an important consideration, particularly when it is desirable to reduce manufacturing cost of each flexible plastic fluid container unit. Thus, while it is possible to manufacture fluid containers having necked-down fluid-discharge portions, as is disclosed in U.S. Pat. Nos. 3,815,794 and 3,878,977, both to Carlisle, and U.S. Pat. No. 4,163,509 to Amneus, it is in most situations desirable to produce flexible-plastic fluid containers that are generally rectangular in shape. Indeed, such a shape tends to reduce material waste and production cost per flexible-plastic fluid container unit. The flexible-plastic fluid containers disclosed in U.S. Pat. No. Re. 24,251 to Kaplan et al. and U.S. Pat. No. 4,491,245 to Jamison disclose flexible-plastic fluid containers that are generally rectangular in shape. Unfortunately, in flexible-plastic fluid containers of this type, undesired container deformation tends to interfere with desired fluid-discharge.
For example, in certain flexible plastic fluid containers--such as those having flexible sidewalls, a closed bottom, spaced-apart deformable side-edge margins, and a deformable upper-edge margin which is unitary with each of the side-edge margins and which defines a fluid-discharge passageway--deformation of that portion of the upper-edge margin defining the fluid-discharge passageway can occur upon application of pressure to the fluid container. Such deformation typically restricts fluid flow through the discharge passageway and thus is a matter of annoyance to the user. Moreover, and based upon the configuration of the particular fluid passageway, such deformation can at times substantially reduce the effective fluid-discharge rate from the container, whereby such fluid rate reduction renders the fluid container unacceptable for its intended use.
The present invention solves just this sort of a problem.